KVM: x86: Fix APIC map calculation after re-enabling

Update arch.apic_base before triggering recalculate_apic_map. Otherwise
the recalculation will work against the previous state of the APIC and
will fail to build the correct map when an APIC is hardware-enabled
again.

This fixes a regression of 1e08ec4a13.

Cc: stable@vger.kernel.org
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index dec48bfaddb8..1673940cf9c3 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1350,6 +1350,10 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
                 return;
         }
 
+        if (!kvm_vcpu_is_bsp(apic->vcpu))
+                value &= ~MSR_IA32_APICBASE_BSP;
+        vcpu->arch.apic_base = value;
+
         /* update jump label if enable bit changes */
         if ((vcpu->arch.apic_base ^ value) & MSR_IA32_APICBASE_ENABLE) {
                 if (value & MSR_IA32_APICBASE_ENABLE)
@@ -1359,10 +1363,6 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
                 recalculate_apic_map(vcpu->kvm);
         }
 
-        if (!kvm_vcpu_is_bsp(apic->vcpu))
-                value &= ~MSR_IA32_APICBASE_BSP;
-
-        vcpu->arch.apic_base = value;
         if ((old_value ^ value) & X2APIC_ENABLE) {
                 if (value & X2APIC_ENABLE) {
                         u32 id = kvm_apic_id(apic);